Protecting and interrupting device for electric circuits



April 7, 1931. A. cs. STEINMAYER 1,799,198

. PROTECTING AND INTERRUPTING DEVICE FOR ELECTRIC CIRCUITS Filed Nov. 2, 1925 2 Sheets-Sheet 1 0/ 43 42 30 O v I) 0 a y m Evy fl w,

April 1931. A. G. STEINMAYER 1,799,198

PROTECTING AND INTERRUPTTNG DEVICE FOR ELECTRIC CIRCUITS Filed Nov. 2, 1923 2 Sheets-Sheet 2 Q Rh & O O

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Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE ALWIN G. STEINMAYER, OF CHICAGO, ILLINOIS, ASSIGNOR TO ELECTRICAL ENGINEERS EQUIPMENT CO., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS PROTECTING AND INTERRUPTING DEVICE FOR- ELECTRIC CIRCUITS Application filed November 1-, 1923. Serial No, 672,240.

This invention relates to an improved protecting and interrupting device for electric circuits.

In electrical distribution systems it is usually necessary to provide some means for protecting the lines and connected apparatus against various potential disturbances. Resistor units are commonly employed in transformer circuits, for example, for protecting the transformer line and apparatus against high voltages and abnormal conditions in the main line. Suitable means are also usually required in the circuit in which the resistor is arranged, whether it be in the transformer circuit or in another part of the system, for interrupting the current flow. For this purpose it has heretofore been customary to employ a switch in addition to the resistor unit. To provide for interrupting the circuit by means of the resistor unit itself has required considerable alteration in the structure of the resistor unit. This has necessitated carrying on hand two types of resistors. Unless the one at hand was of the desired type it could not be employed for interrupting the circuit and replacement of the unit adapted for interrupting the circuit has had to be with a unit of the same type.

I provide a device to which any of several various standard resistors may be conveniently connected without altering the structure of the resistor and which with the resistor so connected permits use of the same for opening and closing the circuit as desired. The resistor may be replaced with an other of the same type or it may be replaced with any other of several types of resistors Without changing the structure of the resistor or of the interrupting device. Only one type of resistor need be kept on hand for use where it is desired to interrupt the circuit with same or where such interruption is not desired or where several types of ordinary non-interrupting resistors are on hand any one may be employed in the initial installation of the device or they may be used at Interruption of the circuit with the device may be had manually or mechanically and by mechanical interruption I intend to include various automatic and non-automatic interruption arrangements.

Another feature of the invention is the provision for mounting and using a fuse with the interrupting and protecting device where I desirable.

The structural details for permitting the foregoing are important and are made the subject matter of certain of the appended claims. These include in their more specific aspect a blade member comprising an insulating intermediate portion for supporting the resistor and terminal portions carried and spaced laterally hy the insulating intermediate portion. The terminal portions of the blade provide maximum and uniform electrical contact with the line terminals and are preferably free to adjust themselves properly to the sides of the line terminals.

To acquaint those skilled in the art with the manner of constructing and practicing the invention I shall now describe in connection with the accompanying drawings certain specific embodiments of the same.

In the drawings:

Figure 1 is a top plan view of one embodiment of the invention;

Fig. 2 is a side elevational view of the same;

Fig. 3 is a top plan view of another embodiment;

Fig. 4 is a side elevational view of the embodiment shown in Fig. 3, and;

Fig. 5 shows diagrammatically a fragment of an electric circuit with a device embodying my invention connected therein.

Referring now to he structural arrangement of the embodiment shown in Figures 1 and 2, 1 provide a metallic or other suitable base 10 upon which a pair of suitable upright or post insulators 11 and 12 are mounted as by means of base fittings 14 and 15 and bolts 16. Base 10 may be of hollow construction as shown.

At their outer ends insulators 11 and 12 are provided with fittings 18. A pivot lug 19 mounted upon fitting 18 at the outer end of insulator 11 has a projecting base 20 to which is secured a socket terminal 21. A contact terminal 22 similarly mounted on the tively.

outer end of insulator 12 has a similar socket terminal 23. Terminal lugs 19 and 22 are electrically connected into the circuit in which the device is arranged by securing the circuit or line conductors in socket terminals 21 and 23. Terminals 19 and 22 are secured in place by bolts 24 and 25 respec- For connecting and disconnecting terminals 19-22to close and open the circuit as desired, I provide .a blade member comprising a strip of any suitable or preferred insulating material having terminals at its opposite ends. The terminal at one end comprises a pair of conducting blace members 31-31 clamped'on opposite sides of pivot terminal 19 and pivoted thereto by bolt 33. Spring washers 34 hold blade portions 31-31 in firm contact with opposite sides of terminal lug 19. The terminal at the opposite end of insulating strip 30 comprises conducting blades 3232 adapted to contact opposite sides of contact terminal 22 as the blade is moved about bolt 19 into closed position. Blade members 31-31 and 32-32 are floa ing and free to spread and adjust themselves to the surfaces of the terminal lugs to at all times secure firm contact over a maximum area, blades 32 32 being held in firm contact with opposite sides of terminal lug 22 by a pair of bolts 35 and spring washers 36.

The outer ends of blades 32-32 are offset totween the blade members maintains the proper lateral spacing of said members in the operation of the device. Blade members 31-31 and 32-32 are insulated from eachother by the insulating intermediate portion 30 and with sa1d port on, constitute a dummy blade.

The resistor shown in Figures 1 and 2 is of the standard G-E non-interrupting type. 'Its details are immaterial 1nsofar as this 1nvention is concerned. Suffice it to say that it includes a suitable resistance element enclosed in a sleeve or tube 40 provided with ferrules 42 at its-opposite ends and terminals 43 and 44. I mount this unit upon insulating strip 30 by clamping it between arms 45-45 secured at their lower ends to opposite sides 'of strip 30 and having their semi-circular upper ends drawn together about the body of the resistor by a bolt 48. Terminals 43 and 44 are electrically connected to blade members 31-31 and 3232 respectively through conductors which may be secured under bolts 38 as shown. Opening movement of the blade about bolt 33 is limitedby. a stop .68-

having a base portion engaging around terminal lug 19 and secured under bolts 24 and terminating at its upper end in a shoulder, inclined at substantially the angle assumed by the blade when completely open.

From the foregoing it will now be apparent that a standard non-interrupting resistor is combined with a dummy switch blade to provide an interrupting device without altering or changing itsstructure vMounting or supporting arms 45 45 may be formed to hold resistors of different sizes or types or a resistor of another type may be mounted upon insulating strip 30 by removing arms 45-45 and substituting other arms of the desired type or formation.

In Figures 3 and 4 I have'shown a resistor of the standard Westinghouse type-mounted on insulating int-e mediate-portion 30 of the interrupting blade without changingthe stritacture of the resistor or altering the blade except to substitute supporting arms 61-61 of the proper size for supporting arms 45-45.

Te minals 62 and 63 of resistor 60 are con nectec. as beiore to blade members 3131 and 32-32 through conductors 65. 7

In the embodiment shown in Figures 3 and 4 base 10 is lengthened and carries a third insulator 70. Secured upon the base of pivot lug 19 on the outer end of the insulator 11 is a lug 71 carrying a fuse clip 72. The outer end 0t insulator supports a second fuse clip 7 3 between which and fuse clip 7 2 a suitable fuse 7 4 of the Westinghouse or G-E potential transformer or any other suitable type is connected in series with resistor 60. The circuit or line conductors are connected to socket terminals 23 and 7 5.

In Figure 5 I have shown the device of Figures 3' and 4 in a transformer circuit leading from a three phase main circuit 81 to apparatus 82 through a transformer 83. This showing is merely illustrative and not limiting because the device may be employed in ther types of electric circuits and at other points in the circuit. I

lVhile l. have shown the invention-in connection with two types of standard resistors now in common use it is to be understood that other types of resistors may be used. Those shown illustrate the manner of combining the resistor with a dummy blade for interrupting purposes without altering or changing the structure of the resistor, also the advantage of employing various types of resistors interchangeably or at random without altering or changing their structure.

I do not intend to belimited to the precise details shown and described.

I claim:

1. In combination, a pivot terminal, a contact terminal, a first pair of floating. blade members pivotally clamped upon opposite sides of the pivot terminal, a second pair of floating blade members movable into and out of engagement with the opposite sides of the first and second pairs of blade members and contact terminal and having free lateral mounted upon said bar.

movement to adjust themselves to the sides of the terminal, means for pressing the blade m members against said terminals, spacing means secured between and spacing the first and second pairs of blade members, and an electrical device connected electrically between said first and second pairs of'blade members and mounted upon said spacing means.

2. In combination, a pair of stationary switch terminals, two pairs of separate floating blade members, one pair pivoted on one of said terminals and the other pair movable into and out of engagement with the sides of the other terminal, a spacing bar of insulating material between the blade members and an electrical device mounted upon said bar and connected electrically between the two pairs of blade members.

3. In combination, a pivot terminal, a contact terminal, a connecting blade having a relatively rigid intermediate bar, a first pair of floating blade members secured upon opposite sides of one end of said bar and pivotally clamped upon opposite sides of the pivot terminal, a second pair of floating blade members secured upon opposite sides of the opposite end of said bar and removable into and out of engagement with the opposite sides of the contact terminal, said second pair of floating blade members having free lateral movement independently of said first pair of blade members to adjust themselves to the sides of the contact terminal independently of the pivot terminal and the engagement of the cooperating blade members therewith, spring means for pressing said second blade members against the contact terminal, and means on said bar electrically connecting said first and second pair of floating blade members.

4. In combination, a pivot terminal, a contact terminal, a connecting blade having a relatively rigid intermediate bar, a first pair of floating blade members secured upon opposite sides of one end of said bar and pivotally clamped upon opposite sides of the pivot terminal, a second pair of floating blade members secured upon opposite sides of the opposite end of said bar and movable into and out of engagement with the opposite sides of the contact terminal, said second pair of floating blade members having free lateral movement independently of said first pair of blade members to adjust themselves to the sides of the contact terminal independently of the pivot terminal and independently of the engagement of the cooperating blade members therewith, spring means for pressing said second blade members against the contact terminal, said relatively rigid intermediate bar being formed of insulating material, and an electrical device connected electrically between said In witness whereof, I hereunto subscribe y name this 29th day of Oct, 1923.

ALWIN G. STEINMAYER. 

